The invention relates a method for enabling a user to select a particular option from a set of selectable options, the method including the steps of:
displaying the set of selectable options at respective option positions; PA1 while allowing the user to physically point at the particular option, taking an image of the user; PA1 ascertaning from the image whether the user points at the particular option; and PA1 if such is the case, concluding that the user has selected the particular option. PA1 a video screen for displaying the set of selectable options at respective option positions; PA1 a camera for taking an image of the user; PA1 an ascertaining unit for ascertaining from the image whether the user points at the particular option; and PA1 a concluding unit for concluding that the user has selected the particular option, in the case that the ascertaining means have ascertained that the user points at the particular option. PA1 the style of interaction is different: in the known method poses that cause a particular silhouette result in a corresponding command and action in the application whereby there is no natural correspondence between the pose and the resulting action, while the present invention provides for natural pointing to an option that is to be selected; PA1 in the known method, the poses and the position of the body are restricted in order to assure that the silhouette of the respective body parts are in the corresponding regions of the image, while the present invention is very liberal in the position and poses the user may assume; PA1 in the known method the analysis of the poses of the user is carried out in the 2 dimensions of the image only, while in the present invention the poses of the body are determined in the 3 dimensional space in which the user interacts thus providing an interface that is very intuitive to the user since it conforms to the human sense of the world. PA1 determining the distance between the option position of the particular option and the foot position; PA1 determining a first angle between the projection of the arm of the user and the projection of the long axis of the body of the user; and PA1 determining a second angle between the arm of the user and the plane of the image on the basis of an estimated arm length of the arm of the user and a determined length of the projection of the arm. The steps of determining the distance between the body and the particular option, on the basis of the foot position, and of determining the position of the pointing body feature with respect to the body, on the basis of the two angles of the pointing arm, have proven a reliable way for determining the position of this pointing body feature in the 3 dimensional space.
The invention further relates to a system for enabling a user to select a particular option from a set of selectable options, the system including:
Such a method and system are described in U.S. Pat. No. 5,528,263. The known system has a projector to project a video image having one or more selectable options, there called buttons, onto a projection screen. The system comprises a camera that records an image of the image projected on the screen. Furthermore, the system is arranged to compare the camera recorded image with the original image fed to the projector. A user standing next to the projected image interacts with the system by covering the particular selectable option with an object that causes a different light reflection than the projection screen. The object may be the user's hand or a dedicated pointing device like a pen or a ruler. When comparing the camera image with the original image, the covering of the particular option is noticed and an action corresponding with that option is executed by the system. This may be the projection of a next video image in a series of images forming a presentation. In this known system, the camera needs to record the projected video image and the user at the same time in a single frame. This restricts the movements of the user who must remain in the vicinity of the projection screen. Furthermore, the user must cover in the projected image the particular option to indicate the selection of this option. This also requires the user's presence close to that option. Furthermore, the user must take care not to accidentally cover this option or another option on the screen with part of his or her body and must avoid blocking the sight of the camera on the option or options on the screen. So for interaction with the known system, the area in which the user can move and the position of the selectable options are restricted.